```html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>NexusTech | Innovative Technology Solutions</title>
    
    <style>
        /* ========== CSS VARIABLES ========== */
        :root {
            --primary-color: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary-color: #334155;
            --accent-color: #0ea5e9;
            --neutral-light: #f1f5f9;
            --neutral-dark: #0f172a;
            --text-color: #1e293b;
            --text-light: #64748b;
            --max-width: 1200px;
            --spacing-xs: 0.5rem;
            --spacing-sm: 1rem;
            --spacing-md: 2rem;
            --spacing-lg: 3rem;
            --spacing-xl: 4rem;
            --border-radius: 8px;
            --shadow-sm: 0 2px 6px rgba(0,0,0,0.1);
        }
        
        /* ========== BASE STYLES ========== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: white;
        }
        
        h1, h2, h3, h4 {
            line-height: 1.2;
            font-weight: 700;
            margin-bottom: var(--spacing-sm);
        }
        
        h1 {
            font-size: 2.5rem;
        }
        
        h2 {
            font-size: 2rem;
        }
        
        p {
            margin-bottom: var(--spacing-sm);
        }
        
        a {
            color: var(--primary-color);
            text-decoration: none;
            transition: color 0.3s ease;
        }
        
        a:hover {
            color: var(--primary-dark);
        }
        
        img {
            max-width: 100%;
            display: block;
        }
        
        /* ========== LAYOUT ========== */
        .container {
            width: 90%;
            max-width: var(--max-width);
            margin: 0 auto;
        }
        
        .flex {
            display: flex;
            flex-direction: column;
        }
        
        .grid {
            display: grid;
            gap: var(--spacing-md);
        }
        
        /* Header/Footer layout */
        header, footer {
            padding: var(--spacing-md) 0;
        }
        
        section {
            padding: var(--spacing-lg) 0;
        }
        
        /* ========== COMPONENTS ========== */
        /* Header and Nav */
        header {
            background-color: white;
            box-shadow: var(--shadow-sm);
            position: sticky;
            top: 0;
            z-index: 100;
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--neutral-dark);
        }
        
        .nav-links {
            display: flex;
            list-style: none;
            gap: var(--spacing-md);
        }
        
        .nav-link {
            color: var(--secondary-color);
            font-weight: 500;
            padding: var(--spacing-xs) var(--spacing-sm);
        }
        
        .nav-link:hover, .nav-link:focus {
            color: var(--primary-color);
        }
        
        /* Hero Section */
        .hero {
            background: linear-gradient(135deg, rgba(0,0,0,0.7), rgba(0,0,0,0.3)),
                url('https://images.unsplash.com/photo-1467232004584-a241de8bcf5d?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            text-align: center;
            min-height: 80vh;
            display: grid;
            place-items: center;
            margin-top: -1px; /* Fixes pixel gap */
        }
        
        .hero-content {
            padding: var(--spacing-lg);
            max-width: 800px;
        }
        
        .hero h1 {
            font-size: 3rem;
            margin-bottom: var(--spacing-md);
        }
        
        .hero p {
            font-size: 1.25rem;
            margin-bottom: var(--spacing-lg);
        }
        
        .btn {
            display: inline-block;
            padding: 0.8rem 2rem;
            border-radius: var(--border-radius);
            background-color: var(--accent-color);
            color: white;
            font-weight: 600;
            border: none;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }
        
        .btn:hover {
            background-color: #0284c7;
        }
        
        /* Features Section */
        .features {
            background-color: var(--neutral-light);
        }
        
        .section-title {
            text-align: center;
            margin-bottom: var(--spacing-lg);
            position: relative;
        }
        
        .section-title::after {
            content: '';
            display: block;
            width: 60px;
            height: 4px;
            background-color: var(--accent-color);
            margin: var(--spacing-sm) auto;
        }
        
        .features-grid {
            grid-template-columns: 1fr;
        }
        
        .feature-card {
            background: white;
            border-radius: var(--border-radius);
            padding: var(--spacing-md);
            box-shadow: var(--shadow-sm);
        }
        
        .feature-icon {
            width: 60px;
            height: 60px;
            margin-bottom: var(--spacing-sm);
            background-color: var(--neutral-light);
            border-radius: 50%;
            display: flex;
            justify-content: center;
            align-items: center;
            font-size: 1.5rem;
            color: var(--accent-color);
        }
        
        .feature-title {
            font-size: 1.5rem;
            color: var(--neutral-dark);
        }
        
        /* Footer */
        footer {
            background-color: var(--neutral-dark);
            color: white;
            text-align: center;
        }
        
        .social-links {
            margin: var(--spacing-md) 0;
            display: flex;
            justify-content: center;
            gap: var(--spacing-md);
        }
        
        .social-icon {
            color: white;
            width: 40px;
            height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            background-color: rgba(255,255,255,0.1);
            transition: background-color 0.3s ease;
        }
        
        .social-icon:hover {
            background-color: var(--accent-color);
        }
        
        footer p {
            color: var(--text-light);
            margin-top: var(--spacing-md);
        }
        
        /* ========== RESPONSIVE LAYOUT ========== */
        @media (min-width: 768px) {
            .features-grid {
                grid-template-columns: repeat(3, 1fr);
            }
            
            .hero h1 {
                font-size: 3.5rem;
            }
            
            .flex {
                flex-direction: row;
            }
        }
        
        @media (min-width: 992px) {
            .hero h1 {
                font-size: 4rem;
            }
        }
    </style>
</head>
<body>
    <!-- Skip to Main Content Link -->
    <a href="#main-content" class="skip-link">Skip to main content</a>

    <!-- Site Header -->
    <header role="banner">
        <div class="container nav-container">
            <div class="logo">NexusTech</div>
            <nav role="navigation" aria-label="Main Navigation">
                <ul class="nav-links">
                    <li><a href="#" class="nav-link" aria-current="page">Home</a></li>
                    <li><a href="#" class="nav-link">Solutions</a></li>
                    <li><a href="#" class="nav-link">About</a></li>
                    <li><a href="#" class="nav-link">Contact</a></li>
                </ul>
            </nav>
        </div>
    </header>

    <!-- Main Content -->
    <main id="main-content">
        <!-- Hero Section -->
        <section class="hero" role="region" aria-labelledby="hero-heading">
            <div class="container hero-content">
                <h1 id="hero-heading">Innovating Tomorrow's Solutions Today</h1>
                <p>Creating cutting-edge technology solutions for forward-thinking enterprises</p>
                <a href="#" class="btn">Discover Our Products</a>
            </div>
        </section>

        <!-- Features Section -->
        <section class="features" role="region" aria-labelledby="features-heading">
            <div class="container">
                <h2 id="features-heading" class="section-title">Advanced Technology Solutions</h2>
                <div class="features-grid">
                    <article class="feature-card" role="region" aria-labelledby="feature1-heading">
                        <div class="feature-icon">&#x1F4A1;</div>
                        <h3 id="feature1-heading">Cloud Infrastructure</h3>
                        <p>Enterprise cloud solutions designed for scalability and enhanced security built for your specific needs.</p>
                    </article>
                    
                    <article class="feature-card" role="region" aria-labelledby="feature2-heading">
                        <div class="feature-icon">&#x1F680;</div>
                        <h3 id="feature2-heading">AI & Automation</h3>
                        <p>Transform your operations with our machine learning models and process optimization technology.</p>
                    </article>
                    
                    <article class="feature-card" role="region" aria-labelledby="feature3-heading">
                        <div class="feature-icon">&#x1F310;</div>
                        <h3 id="feature3-heading">Data Analytics</h3>
                        <p>Advanced tools to gather, analyze, and visualize data for meaningful business insights.</p>
                    </article>
                </div>
            </div>
        </section>
    </main>

    <!-- Site Footer -->
    <footer role="contentinfo">
        <div class="container">
            <div class="social-links">
                <a href="#" class="social-icon" aria-label="Twitter"><span role="img" aria-hidden="true">&#x1F426;</span></a>
                <a href="#" class="social-icon" aria-label="LinkedIn"><span role="img" aria-hidden="true">&#x1F4BC;</span></a>
                <a href="#" class="social-icon" aria-label="GitHub"><span role="img" aria-hidden="true">&#x1F4BB;</span></a>
            </div>
            <p>&copy; 2023 NexusTech Solutions. All rights reserved.</p>
            <p>Advanced technology for modern enterprises</p>
        </div>
    </footer>
</body>
</html>
```